The etiology and pathogenesis of IBD are complex and multifactorial. Accumulating evidence has indicated that sustained intestinal infections, mucosal barrier defects, mucosal immune dysregulation, genetic and environmental factors are involved in the disease process. Among these, dysfunction of the mucosal immune system plays an important role in the pathogenesis of IBD.
IBD is conventionally regarded as involving autoimmune reactions, for which there are known and suspected genetic predispositions. However, that raises the question of which environmental factors trigger the autoimmune mechanisms to cause disease in the individual patient. Many theories suggest reactions to microorganisms in the gut.
There is an unmet need for medicaments that can be used to treat inflammatory bowel diseases more effectively. The development of new treatments, however, has been limited by incomplete knowledge of the underlying pathology of these diseases.